Process of preparing sulphonated organic detergents



Patented Feb. 5, 1946 PROCESS OF PREPARING SULPHONATED ORGANIC DETERGENTS Russell Park McGhie, Brooklyn, N. Y., asslgnor to Colgate-Palmolive-Peet Company, Jersey City, N. J., a corporation of Delaware No Drawing. Application May 19, 1942, 7 Serial No. 443,639

The present invention relates to a M 65 o making detergent compositions and, more particularly, to a process of preparing sulphated and sulphonated organic materials having good wetting, emulsifying and deterging properties.

Synthetic detergents, particularly those comprising sulphated and/or sulphonated organic compounds, have been made and used for many years, but one of the great dimculties in their manufacture has been the tendency of the materials in the course of manufacture, particularly in aqueous solution, to attack metal parts, such as tanks, drying rolls, spray nozzles and the like, especially those made of iron and steel. This tendency, which is particularly objectionable in compositions having a pH below 7.0, not only results in pitting and corroding away of metal parts, but also causes discoloration of the prodnot and a decrease in its'ability to produce foam. The product, as heretofore produced, cannot be stored in metal vessels, except in stainless steel tanks or other expensive corrosion-proof alloys, without corroding the containers. Even though the containers are lined, enamelled, painted or nickel plated. they are still unsuitable for storing this material, as the wetting power of the solution is often so great as to penetrate the minute ports of the coating, loosening the coating from the metal and corroding the metal walls, and as the lining or coating often cracks or breaks for one reason or another to expose the metal wall beneath. Moreover, the action of the sulphonated material upon the metal introduces impurities which result in deterioration of the product, both in color and in clarity of aqueous solutions prepared therefrom.

It is an object of the present invention to provide a process for manufacturing detergent compositions of high clarityand good color stability in aqueous solution.

It is another object of the invention to provide a process of manufacturing sulphated and sulphonated organic materials of light color without corroding ordinary metal apparatus.

Other objects and advantages of the present invention will be apparent from the following description.

According to this invention, it has been found that the introduction of an inorganic phosphate, in any proportion, during the preparation of nonsoap detergents, emulsifiers and wetting agents of the type of sulphated or sulphonated organic materials avoids corrosion of the metal parts of the manufacturing equipment and provides a product which in aqueous solution is clear, colorstable and highly soluble and which is substantially non-corrosive. It is preferred to introduce the phosphate at a point in the manufacture prior to hydrolysis and/or neutralization of the sulphonated (true sulphonated and/or sulphated) material, and, when adding phosphatic material prior to neutralization with alkali, phosphoric acids may replace phosphate salts for such addition, as will be described in greater detail hereinafter. Such use of phosphoric acids to be neutralized to phosphate salts for incorporation with sulphonated material in detergent compositions is not to be confused with the use of phosphoric acids in phosphating organic compounds, either with or without sulphonation, whether the sulphonation is prior to, simultaneous with or subsequent to said phosphation, as disclosed by the prior art.

The sulphated or sulphonated organic compounds prepared by the process of the present invention may be made from organic materials which are applicable for sulphonation (true sulphonation and/or sulphation) especially those having about eight to about twenty-six (and preferably about twelve to about twenty) carbon atoms to the molecule, including fatty oils, unsaturated fatty acids, mineral oils, mineral oil extracts, monoand di-glycerides, partial esters or ethers of polyglycols, esters or ethers of glycols, polyglycols and polyalcohols, aromatic and alkylated aromatic compounds, alcohols and olefines, coal tar distillates, and numerous other organic compounds and mixtures of compounds. Such compounds can be sulphonated by any of several methods and may form any of several products, depending upon the method of sulphonation employed. The sulphated or sulphonated organic compounds include sulphonated mineral oil; conventional mineral oil refinery sludges; sulphonated mineral oil extracts, including the products described in U. S. Patents. Nos. 2,149,661, 2,149,662 and 2,179,174; sulphonated fatty acids and oils, including sulphonated castor oil, sulpho-ricinoleic acid, sulphonated olive oil, and sulpho-oleic acid; aliphatic sulphonates and sulphates, including cetyl sulphuric acid, dodecyl acid sulphate, and tetradecanehydroxy sulphonic acid-1,2; aliphatic other and ester sulphonates including the dodecyl ether of hydroxy ethylsulphonic acid," the cetyl ether of glyceryl sulphonic acid, tallow monoglyceride monosulphate, and coconut oil fatty acid monoesters of beta methyl glycerine sulphonic acid; sulphonates prepared by treatment aforganic materials with sulphur dioxide and chicrine in the presence of light and hydrolysis of the .product; sulphonates prepared by treatment of organic bodies with sulphuryl chloride and an activating agent in the presence of light and hydrolysis of the product; fatty acid amides of amino alkyl sulphonic acids, including lauric amide of taurine and tall 011 acid amide of amino glyceryl sulphonic acid; sulphonic acids of naphthenes and naphthenic acids; lignin sulphonic acids; aromatic and alkylated aromatic sulphonic acids, including naphthalene sulphonic acid, octadecyl benzene sulphonic acid, and dodecyl naphthalene sulphonic acid; the product of a mineral oil extract sulphonated while dissolved in liquid sulphur dioxide; and innu merable other organic sulphonic and sulphuric acid derivatives or mixtures thereof. These organic sulphate and true sulphonate compounds include those in which the organic radicals of the molecule are unsubstituted or those which contain substituents, such as halogens, halogenoids, hydroxyls, nitrogen-containing groups, acyl groups, acyloxy groups, alkoxy groups, etc. Of these sulphated and sulphonated materials, the most suitable for preparation according to the process of the present invention are normally non-alkaline, and especially those having carboxylic ester linkages, including the sodium salts of the sulphuric acid esters of coconut oil fatty acid monogiycerides, tallow diglyceride monosulphate, and stearyl monoesters of beta methyl glycerine sulphonic acid.

The inorganic phosphates, which may be introduced during the preparation of sulphonated organic materials to achieve the desirable results described are water-soluble phosphates, including primary, secondary and tertiary sodium orthophosphate and the sodium salts of tetraphosphoric, tripolyphosphoric and pyrophosphoric acids, wholly or partially neutralized, as well as the other alkali metal and ammonium salts oi orthophosphoric, tetraphosphoric, trlpolyphosphoric and pyrophosphoric acids, wholly or partially neutralized. It is preferred to use salts of phosphoric acids capable of forming water-solu-" ble calcium salts. Any one or more of the phosphates mentioned may be added to the reaction mass, and/or other compounds breaking down or reacting with the sulphonated materials to provide saidphosphate salts may be employed. Where the sulphonated compounds are to be neutralized subsequent to addition of phosphatic material, as is preferred, the phosphate salts may be replaced by the corresponding acids.

Although the incorporation in these detergent compositions of only about 0.001% to about 0.5% by weight of inorganic phosphate based upon the weight of active ingredient has the advantages of providing the composition with unusually high clarity in aqueous solution, substantial freedom from corrosive effect, good color stability, high solubility and improved foaming, without substantial modification-of the detergent and other desirable properties of the active ingredient, and of stabilizing the material in storage in metal tanks and in drums for shipment, particularly in concentrated solutions of the sulphonates, say, in aqueous solutions containing about 5% to about of active ingredient, it is desirable during manufacture to employ larger proportions of phosphate to active ingredient, say, of the order of about 10% to about 50% and even as high as 100% or higher, to avoid corrosion of metal equipment.

The neutralizing step may be carried out in batch operation or ccntinuouslyand/or in the presence of previously neutralized material, and water or aqueous solutions of salts and/or acids or alkalies may be used therefor. Alkaline agents are most commonly employed, a sulphonate salt resulting from the neutralization, and agents suitable therefor include sodium and potassium hydroxides, carbonates, silicates, etc., pyridine, methyl morpholine, piperidine, alkyl amines, alkanolamines and other organic and inorganic bases and alkaline materials, and mixtures oi these. The alkaline agent may be introduced in aqueous solution, in alcoholic solution, or in solutions of other solvents, or may be substantially anhydrous and/or substantially undiluted. The amount of solvent introduced with the alkaline or saponifying a ent has a bearing upon the water or organic solvent content of the finished product.

The neutralization may be carried out by intimately mixing sulphonated material with an alkaline agent in the presence of inorganic phosphate in a reaction vessel under atmospheric, superatmospheric or reduced pressure. The inorganic phosphate may be admixed with the sulphonate salts thus formed by introducing it into the reaction mixture in the sulphonating vessel, either separately or mixed with the sulphonating agent, and/or it may be admixed by mixing the phosphate with the sulphonated material and/or the neutralizing agent before contacting, and/or by simultaneously passing into the neutralizing vessel a solution containing phosphate salts.

When adding the phosphatic material prior to neutralization, the phosphoric acids corresponding to the phosphate salts hereinbefore described as suitable for use in the new process of the invention may replace all or part of the phosphate salts. However, when employing a phosphoric acid, especially during the sulphonating step, the proportion of phosphoric acid to sulphonating agent must be sufficiently low to avoid phosphation of a substantial amount, if any, of the organic compound under the operating conditions. Thus, an amount of phosphoric acid equivalent to from about 10% to about 35% of the weight of sulphonating agent has provided satisfactory results.

Heating and/or cooling means associated with the neutralizing vessel may be provided, as desired. Where the product is to be dried, heat may advantageously be supplied to the reaction mixture in the neutralizing vessel. The heat of neutralization may alone be sumcient to raise the mixture to the desired temperature, depending upon the materials employed and the subsequent operating conditions, or heat from external sources maybe supplied. Either or both of the reactants may be preheated by steam or other means before being run into the vessel, and/or the mixture may be heated during and/or after admixture. The neutralization step may also be operated in conjunction with a spraying step for obtaining substantially granular and/or hollow particles, the material from the reaction vessel being forced in fluid form into a spinner bowl or spray nozzle, and, upon atomization, coming in contact in a spray tower with a current of inert gas, preferably air. The air current may be heated, and it is preferably passed through the tower countercurrent to. the sprayed material, although concurrent passage of the air is also contemplated.

Another method of neutralization is to mix the reactants in a mixing vessel with inorganic phosphates, and then to pass the neutralized product containing phosphate salts to a vapor separation chamber at a lower pressure. The sulphonated material and neutralizing agent may also be reacted at an elevated temperature under pressure and in the presence of phosphates and then flashed into a vapor separation chamber at a lower pressure, whether superatmospheric, atmospheric or reduced, thereby vaporizing any solvent present, if used, and any vaporizable reaction product. A suitable condensation system can be provided to recover vaporized materials.

The sulphonated material and the neutralizing agent may be forced under relatively high pressures through a reaction conduit, such as a pipe, together with inorganic phosphates and with or "without the application'ofheat. The materials are thoroughly contacted in the conduit, and, operating preferably continuously, the neutralized sulphonate salts and the phosphates can be discharged to a low pressure zone, preferably through a constricted outlet or nozzle. Heat may be supplied to the pipe, if necessary, to raise the temperature of water or other solvent therein to the vaporization point at the pressure within the pipe, and the temperature and pressure at any point in the pipe may be kept substantially constant or may be varied in a cyclic manner for the purpose of creating greater turbulence in the'reaction conduit by alternately establishing and destroying a vapor phase therein. Upon flashing into the lower pressure zone, the heat of the reaction product is employed to vaporize the water or other solvent at the low pressure of the separation chamber, and the vaporized material goes off at the top, while the sulphonate salt containing phosphates mixed therewith and having at least a portion of water and other volatile materials removed, falls to the bottom.

By contacting the neutralization mixture, momentarily and just before discharge into the low pressure flash zone, with an inert gas at a considerably higher temperature, less heat need be supplied to the neutralization and preheating conduit and/or. a higher absolute pressure may be employed in the separation chamber. The contact of the reaction mixture with an inert gas, such as superheated steam, kerosene vapor, carbon dioxide, flue gases, stack gases, etc., is preferably made at extremely high velocity and for a minimum time period before introduction into the flash chamber. The contacting can be advantageously accomplished by a nozzle designed to permit intimate but only momentary direct contact and a minimum of indirect contact before admission into the flash chamber. Employing this modification, the length of the hydrolyzing and/or neutralizing conduit can be appreciably shortened, if desired, and less heat need be supplied thereto by external heating of the conduit and/or by preheating of the sulphonated material and/ or the neutralizing agent.

In another procedure, it is possible, by means of superheated steam or other inert gas, to supply suilicient heat at anoptimum temperature and velocity in order to eifect instantaneous hydrolysis and/or neutralization along with flash distillation of the materials to be withdrawn as a vapor. This procedure avoids plugging of pipes and nozzles, because the aqueous mixture is not under flashing conditions for any appreciable time before introduction into the nozzle, where it attains high velocity and adequate heat in momentary time before its discharge into the flash chamber.

Although the present invention is especially directed to concentrated solutions of the compositions provided, the proportions of superheated steam introduced into the nozzle in these various modifications can be so regulated in practice that a dry product or a hydrated product of any degree of hydration can be produced. The product may be made in a more or less finely divided condition, which permits its ready transformation into flakes or other physical forms, for example, by passing between a pair of properly spaced rolls, or by pressing into cakes, or by other means, with or without addition or modifying agents.

The presence of inorganic phosphates during neutralization and subsequent operations substantially prevents corrosion of metal parts of apparatus and equipment, including mixers and tanks, pipe lines and conduits, spray nozzles, spinner bowls, drying rolls, etc., even at the higher temperatures disclosed. Furthermore, due to the presence of the phosphates, the product retains its original color.

Adjuvant materials may be admixed with the sulphonated salts containing a small proportion of hosphates thus formed by mixing the adjuvant materials with the sulphonated organic compounds and/ or the neutralizing agents before neutralization or flashing, by simultaneously flashing a second solution containing such adjuvant materials, and/or by mixing the flnal product therewith. Such adjuvant materials may include fatty acid soaps, resin acid soaps, naphthenic and alkylated naphthenic acid soaps, alkaline soap builders, additional water-soluble, water-softening compounds of acids of phosphorus, and other salts including sodium carbonates, sodium silicates, borax, sodium bicarbonate, sodium sulphate, sodium chloride, sodium acetate. sodium hydochlorite, sodium thiosulphate, sodium perborate, sodium tartrate, sodium citrate, sodium oxalate and the corresponding ammonium. substituted ammonium and potassium salts of the corresponding acids; insecticidal, germicidal, styptic and medicinal agents, including aluminum chloride, mercuric chloride and various copper and lead salts; coloring agents, abrasives, fillers and water-dispersible gums, including dyes, lakes, pigments, silica, kieselguhr, silica gel, feldspar, precipitated chalk, pumice, infusorial earth, bentonite, talc, starch, Irish moss, sugar, methyl cellulose, agar, gum tragacanth, gum arabic and polyvinyl alcohol; liquids, such as ethyl alcohol, glycerol, eyclohexanol, naphtha, benzene, kerosene, turpentine, pine oil, decalin, and tetralin, and the like. The type of addition agent will depend upon the ultimate use of the composition.

The following examples, described herein, are merely illustrative of the present invention, and it will be understood that the invention is not limited thereto.

Example I About 154 pounds of pyrophosphoric acid is dissolved in about 666 pounds of fuming sulphuric acid of about 102.8% strength. The acid mixture is then mixed with about 33 pounds of anhydrous (about 99.5%) glycerine in a mixer of ordinary steel and equipped with cooling means to keep the temperature at about 30 C. The resulting mixture is then passed to a similar mixer and is there mixed with about 216 pounds of coconut oil and about 272 pounds of tallow, heating during the mixing operation to about 50 C. The agitation is continued for about forty minutes, after which the reaction product is passed to a neutralization d accuser v tank of ordinary steel and is there mixed with About 3 parts oi a Pennsylvania white mineral oil of paramn base and having an average molecular weight of about 235 is treated at below about C. with a gaseous mixture of approxi= mately 1 part by weight of chlorine and about 2 parts by weight of sulphur dioxide in the pres once of light. The time oi treatment is regulated to effect a weight increase of about at which point the reaction mass contains approximately 50% of mineral oil sulphonyl chlorides. The

. crude material thereby formed is simultaneously purified and extracted with about 2 parts of liquid sulphur dioxide, the liquid sulphur dioxide phase being continuously removed. The sul= phonyl chlorides contain some of the unsuiphon= ated oil, and separation can be accomplished by re-extracting the sulphur dioxide solution with ligroin. The sulphur dioxide is then removed, and about 2.25 parts of syrupy pyrophosphoric acid having about 82% phosphorus pentoxide is added to the residue. The resulting mixture is hydrolyzed and neutralized by stirring with an aqueous 30% solution of sodium hydroxide at a temperature of about 90 C... and the mixture is diluted so as to contain about 10% of the sulphonated product. The suiphonate solution is treated with sulphuric acid to neutralize excess alkali, thus forming a certain amount of sodium sulphate. Additional sodium sulphate is also added to bring the salt content to a desired pro-= portion. The solution is passed to steam-heated drying rolls of ordinary steel, and a flaky, snow= white product is obtained.

The use of the term sulphonated" with reference to organic compounds and detergents in the following claims will be understood to include sulphated as well as true sulphonated materials. Similarly, the terms sulphonating and "sulphonation are intended to include sulphating and sulphation as well as true sulphonating andsulphonation.

Although the present invention has been de scribed with reference to particular embodiments and examples, it will be apparent to those skilled in the art that variations and modifications of this invention can be made and that equivalents can be substituted therefor without departing from the principles and true spirit of the invention. Such variations and modifications are believed to be within the scope of the present specification and within the purviewoi the appended claims.

I claim:

1. In the process of preparing detergent com positions in iron-containing equipment comprising sulphonating organic compounds and non tralizing the product of said sulphonation, the improvement which comprises carrying out said neutralization in the presence of phosphatic material from the group consisting of phosphoric acids and watersoluble salts thereof in an amount sufilcient to inhibit corrosion of said equipment but insufiicient to cause substantial phosphation of the organic compounds under the operating conditions.

2. In the process of preparing detergent compositions in iron-containing equipment comprising sulphonating organic compounds and neutralizing the product of said sulphonation, the I improvement which comprises introducing prior to said neutralization an amount of a water-soluble inorganic phosphate salt equivalent to about 10% to about 50% of the weight of the sulphon ated organic compounds.

3. In the process of preparing detergent com positions in iron-=containing equipment compris= ing sulphonating organic compounds and neutrak izing the product of said sulphonation, the im provement which comprises introducing prior to said neutralization an amount of a phosphoric acid equivalent to about 10% to about 50% oi the weight of the sulphonated organic compounds but insufiicient to cause substantial phosphation oi. the organic compounds under the operating conditions.

4. In the process of preparing in iron containing equipment detergents containing alkali metal salts of the sulphuric acid esters of coconut oil fatty acids monoglycerides comprising sulphating coconut oil fatty acids monoglycerides with oleum and neutralizing the product of said sulphation, the improvement which comprises sulphating the coconut oil fatty acids monoglycerides in the presence of an amount of a p osphoric acid equivalent to about 10% to about 50% of the weight of the sulphated monoglycerides but in= su'filcient to cause substantial phosphation of the coconut oil fatty acids monoglycerides under-the operating conditions.

5. In the process of preparing in iron-containing equipment detergents containing a mineral oil sulphonate comprising treating a mineral oil 40 prises introducing prior to neutralization an amount of water-soluble inorganic phosphate salt equivalent to about 10% to about of the weight of mineral oil sulphonate.

6. In the process of preparing a sulphonated organic detergent in ironcor aining equipment comprising sulphonating organic compounds and neutralizing the product of said sulphonation, the improvement which comprises neutralizing the product of said suiphonation in the presence oi a water-soluble inorganic phosphate salt in an amount suficient to inhibit corrosion of said equipment but insuficient to cause substantial phosphation of the organic compounds under'the operating conditions.

i. In the process of preparing a suiphonated organic detergent in iron-containing equipment comprising sulphonating organic compoundsand neutralizing the product of said sulphonation, the

improvement which comprises neutralizing the product of said sulphonation in the presence of a phosphoric acid in an amount suflicient to inhibit corrosion of said equipment but insuflicient to cause substantial phosphation of the organic compounds under the operating conditions.

8. In the process of preparing a sulphonated organic detergent in iron-containing equipment comprising sulphonating organic compounds and neutralizing the product of said sulphonation, the improvement which comprises neutralizing the product of said sulphonation in the presence of an amount of a water-soluble inorganic phosphate salt equivalent to about 10% to about 50% of the weight of the sulphonated organic compounds.

' 9. In the process of preparing detergent compositions in iron-containing equipment comprising suiphonating organic compounds and neutralizing the product of said sulphonation, the improvement which comprises sulphonating the organic compound in the presence of an amount of a water-soluble inorganic phosphate salt equivalent to about 10% to about 50% of the weight of the sulphonated organic compound.

10. In the process of preparing detergent com positions in iron-containing equipment compris- 10 

